1638812144 has 20 divisors (see below), whose sum is σ = 3176783280. Its totient is φ = 818997120.

The previous prime is 1638812137. The next prime is 1638812167. The reversal of 1638812144 is 4412188361.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1638812098 and 1638812107.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8909 + ... + 57939.

It is an arithmetic number, because the mean of its divisors is an integer number (158839164).

Almost surely, 2^1638812144 is an apocalyptic number.

It is an amenable number.

1638812144 is a deficient number, since it is larger than the sum of its proper divisors (1537971136).

1638812144 is a wasteful number, since it uses less digits than its factorization.

1638812144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51128 (or 51122 counting only the distinct ones).

The product of its digits is 36864, while the sum is 38.

The square root of 1638812144 is about 40482.2447994179. The cubic root of 1638812144 is about 1178.9889222850.

The spelling of 1638812144 in words is "one billion, six hundred thirty-eight million, eight hundred twelve thousand, one hundred forty-four".